Molding core



Jan. 5, 1954 w. A. EVANS ETAL 2,664,613-

MOLDING CORE 0. w. EVA/V5 ,2

L. d. SIMS .4 [tom eys 1954 w. A. EVANS ET AL 2,664,613

MOLDING CORE Filed March 15, 1950 2 Sheets-Sheet 2 A Home 3:

Patented Jan. 1 954 I MOLDING CORE Wallace A. Evans, David W. Evans, and Leslie J. Sims, Penarth, Wales; said Sims assignor to said Wallace Alfred Evans and said David I Wallace Evans Application March 13, 1950, Serial No. 149,334

This invention relates to moulding cores and more especially to cores for use in moulding hollow concrete structural members.

It is nowadays considered desirable that cores for moulding hollow concrete structural members should be withdrawable after use and be suitable for repeated use in moulding further members. Various constructions of cores adapted for repeated use in this manner have been proposed and used and it is an object of this invention to provide an improved core which is both comparatively simple in construction and economical m use.

According to the invention a collapsible core for use in moulding hollow concrete and similar members comprises a number of oppositely dis posed pairs of rigid members, the members of each pair being relatively movable towards and away from each other so as to vary the crosssectional dimensions of the core, and means adapted to hold the members of each pair when said members have been moved relatively away from each other.

Further according to the invention a collapsible core for use in moulding hollow concrete and similar members comprises rigid side members which are bodily relatively movable from a position in which they hold other side members spaced fully apart to a position nearer one another in which they permit of relative movement of said other side members towards each other.

The invention will be describedby way of example with referenceto the accompanying drawings in which:

Fig. l "is anend elevation with parts broken away.

Fig. 2 a fragmentary plan view.

Fig. 3 a sectional'elevation on the line III--III of Fig. 1.

Fig. 4 is a sectional IV-IV of Fig. l and Figs. 5a, 5b are diagrammatic views illustrating a device for preventing lateral distortion of sidemembers in a long core during moulding.

Referring to the accompanying drawings, a core comprises two flat plate members or outer members I, 2 each having lateral edge portions Ia, 2a which are so shaped that when the plates are arranged opposite one another the inner surfaces of the edge portions on the top plates on each side of the core converge. Two tubular side or inner members 3, 4 are disposed within the plates or outer members I, 2 so that when the side or inner members 3, 4 are moved apart they force the plates or outer members I, 2, apart. When the side or inner members are moved together the plates I, 2 are able to move towards one another until the flat portions of the plates ride on the side members. Both the plates I,

elevation on the line 2 Claims. (Ci. 128) 2 2 and the side members 3, 4 extend over length .of the core. The relativemovements of the plates or outer members and side or inner members are limited by means of end plates disposed at each end of the core, oneof theseend plates 5 being shown and it is to be understood that the end plate at the other end is similar to the plate 5. The end plate 5 is provided with slots 6, l which are each closed at both ends and pins 8, 9 fixed to and projecting from the side or inner members engage in these slots. Similar slots I8, II which extend at right angles to the direction, of the slots 6, "I are also provided in the end plate and pins I2, I3 which are fixed to and extend from blocks I i, I5 fixed to the plates or outer members I, 2 engage in the slots I0, II.

The pins 8, 8 are suitably formed by screwthreaded bolts which are disposed in discs 16, H which are fixed in the .ends of the side or inner members 3, 4 by counter-sunk screws I8 as shown in Fig. 4. A hole I9 in each disc may be provided for the reception of a duct so that steam or other hot fluid may be circulated through the side or inner members in order to facilitate rapid hardening of the concrete; Spring clips 20 are shown provided for the purpose of holding the bolts 8, 9 in position but'the bolts may be otherwise secured in position in the discs, for example they may be cast in, and, in order to prevent the bolts from turning, they may be provided with flats on their shanks, the bores in the discs being correspondingly shaped. The blocks I4, I5 may be secured to the outer members I, 2 by countersunk screws 2I and screw-threaded bolts are disposed in the'blocks to form the pins I2, I3. Spring clips 20are also arranged to hold the bolts l2, I3 in position in like manner to the arrangement forthe bolts 8, 9; Nuts 22 are provided to engage the bolts 8, 9 and I2, I3 in order to locate the bolts in their outermost position in the slots 6, I and I0, II. The lengths of the slots 6, I are such that the side or inner members 3, 4 are prevented from moving apart to such an extent that the inclined surfaces on the plates or outer members I, 2 which bear on the side or inner members are able to move apart to a distance equal to the outer diameterof the side or inner members. Each flat outer member I, 2 is provided with an inwardly projecting strengthening rib 23.

' When the core is arrangedfor use the side'or inner members 3, i are moved manually apart to the greatest distance permitted by the slots 6, 'I and locked in this position by tightening the nuts 22 on the bolts 8, 9. This movement of the side or inner members is followed by a corresponding movement of the flat outer members I, 2 and these members are also held fixed in position by tightening the nuts 22 on the bolts I2,

the

a moulded concrete member the outer surfaces-of the flat outer members I, 2 are provided with open grooves 24 and after thecoremas been pre-.-.

pared for use by moving the side oninnerm 1-,

bers 3, 4 and the fiat outer members I, 2 apart and tightening the nuts 22, asheet o f pa per or like flexible thin material is wrapped-'roundthe-- core. By this means the core, after beingcollapsed, can readily be withdrawn from a moulded member;

Although the side or inner members 3, 41a re shown. ue. c l nder t..wi1, be. ppr iat ha hese members. may av other urved Shane's While. he. p ates. u r members ma e... armed or. xam l w t e e ses on h ir nner. ur c s. the, or s. o he ifie e t members a h case h wev n, rovidin a w d er i eactiq whereby. them mbers of n pair are a e orewidt w n b memh i he the z ai are moved a a Where the side or inner. members 3, 41 are long inreiationtotheir cross-sectional area and there may be; a; danger of; these members bending nwa dlic un erthet tres si d, by on t during. s ttin the, arran m l us ed by Figs. 5a and 5b may be. employed. In this arrangement, an ar m 2. :i is pivotally mounted on the strengthening rib 2,3 on the lower fiat outer rnernber 2,. The arm 2@carriestransversely pro jecting. rigidarrnsezfi, at the freeend of each on which ismountedaroller 21; These rollers 2jLand arms2 6 are so .dimensionedthat when the side opinnermembers 3, 4 have been moved fully apartthe rollers will just bear on these side members aiter the arm 2 5 has been raisedirom a nosition in which it lie s alongthefiat outer membe Les Q n rokenline niF r tothe upright position as shown. in full linesin E s: 5c and roken es n. F 1bh ssi dmt tmentwi h arm 2 nd ol ers 21 ma efiect t r hit s ast n d. tothe upp enendof the armifiand which pro-. trudes at both ends of; the core as indicated in B h:

arm;2 .5.;and rollers 2] may bearrangedat aa ndfl i ba qreso a a number Q co s may be placed; end to end for. thepurpose of mel in ah em longer han o e. more-por s In-;this,us e. of the core provided by the inven e benuts. 2. at di nt nds g djace cores ai einot tightened, after the arms 25 fhave bee iere ted he uts at h o ds h two ve idcores n y, i tigh en d; hetq e ide membersio ours having been pre ous y pac d. t ouldin -M t will. veuns e od ha he or s d s r ed. max. e, s d or. uldin re nfo ced... oncr te members,. the reinforcement being disposed; in qrmalmanner- The reinforcement plate is also i provided with u sm iqh, nga e, etwee he side memb rs}. t qlnr vent. atera disp cem t memoi ti qnt m atedtbat he. re rov ded y. the inyention 1 willgbe employediin moulding -ma 4 terials other than concrete for example the materials. known as: plastics,

We l im; 1. A. collapsible core for use in moulding hollow concrete and similar members which comprises a pair of oppositely disposed rigid outer members of which at least one member has at each longitudinaledge portion a surface which is incl-inedtowardsand faces the adjacent edge po ion-of t-he other member of the said pair, a pair i oppositely disposed rigid inner members each havinga curved outer surface and disposed loosely" between said outer members, the said members being bodily movable apart to cause the said curved outer surfaces to ride on he. aid nc ined. u a es and h reby. ot or he, Quiet. membersap rt. means.-. umitine. he movement apart- 0. the inner members fstop means ivotelly.mouat a atistw m an ononefof he. ou e m mb ea d an tua in member operable. om. u s de he. or amer he. ai ion means n nd" r m. esi i n h me-$1 n r. mem I n. whi h. n? 91 m ans, a ut on. bath he... m mbe he. nner D3 1,

..Q9 1 s b .w e 0 s ain m u d nei qlilow con e e; and; simi a m mbers w i h: .0m: prises a pair of oppositely disposed rigidouter b s. of wh ch, a ea t one, mber. a at each longitudinal. edge. portion, a; snrface which si tline tq r sarid. faces. he, ad a en d e portionpf theother memberof the said 'et r, a pair of p t dispos d. i i gmemb rs a h a in amt-red mi r ur acent disp sed. oo h i w n aid, termemhert. he id inner m mb rs b nei odil i mq able. a art tq u e he said. curved, outer su'riaces tori'de on the Said inclined surfaces and thereby to..forc.e the.. o,.uter members 7 apart, an; end plate, disposed at .each end of the, core ther said end latte being provided withi closed guide. slots, pins, projecting from each. member. or. each pair and. entering et p. mean m a p tal yx u ti said stop meansronrone of the. outer. members andlan A actuating member. operable fromputside he ra 9. m ve he idi o m n nt d from a position between the inner members in hi h he or mean rab tnn th; hem mb i hs: nner; Ha r.-

WALLACEA, EVANS. DAVID w. EVANS. LESLIE J. SIMS.

r nce i ed n T the. file... is a e?- UNITED STATES PATENTS 

